In 1990, he was assigned to DOJ's National Security Working Group and as an International and National Security Coordinator for the Department as well as legal advisor to the Central Texas Counter Terrorism Working Group. As INSC he worked closely with the FBI and US intelligence agencies on both international and national security related cases, trained federal prosecutors, and has traveled to Kosovo, Qatar, Israel and England to teach foreign judges and prosecutors and investigate international and national security matters. He began teaching at the FBI Academy and US Department of Justice Advocacy Institute in 1985.
In 2000, he took a leave of absence to teach National Security Law and Federal Criminal Law at the University of Texas School of Law and has continued teaching as an adjunct professor at UT Law. He has received several awards for his work including the Department of Justice Directors Award for Superior Performance on two occasions and awards from several government agencies. He has published two books, Cases and Materials on US Law and National Security (2000, third edition 2012) and Defense, Liberty and the Constitution (2005) as well as eleven Law Review Articles on legal issues related to national security.